Process of removing static electricity.



No. 824,339. PATENTED JUNE .26, 1906.

W. H. CHAPMAN. PROCESS OP REMOVING STATIC ELECTRICITY.

APPLICATION FILED NOV. 7, 1904.

.M M i am UNITED s Arns PATENT FFIOE,

WILLIAM HENRY CHAPMAN, OF PORTLAND, MAnvIa'AssIcNOs o CHAPMAN ELECTRIC NEUTRALIZER cOMeANnoF PORTLAND,

MAINE. A CORPORATION OF MAINE.

PROCESS OF. REMOVING STATIC ELECTFII'CITY.

. Patented June 26 1906.

Application filed November 7,1904. emu No. 231,686.

To all whom it may concern.-

Be it known that 1, WILLIAM HENRYCIIAP- MAN, a citizen, of the United States of America, and a resident-of Portland, (lumberland county, State of Maine, have invented certain new and useful 1m rovements in Processes of Removing Static lectricity, of which the following is a specification.

My invention relates to a process for re charged surface an op osing charge which shall be automatically imitedin amount, so as not to reverse the charge on the surface {under treatment, making the neutral condition the only stable condition forthe surface.

I attain my object by the use of two opposing charges of constant polarity applied to conductors of small surface, the one positive and the other-ne ative The charges are of high voltage, an the conductors are located sufficiently near each other so that the material to be treated may be brought'within the range of the convective dischargeof both at the same time and ,sufliciently'far apart to maintain o posing charges and the surface to be neutralized is brought simultaneously within the active influence of both conductors. By this process the-static charge in the material under treatment selects by natural law from one of the conductors a charge of the right kind to neutralize itself;

but it can receive'no more than sufficient toneutralize itself, owing to the action of the I op osing charge.

t is a well-known fact that a conductor of small surface, like a fine wire, when connected with either pole of a Wimshurst machine or other source of electricity of high potential discharges electricity through the surrounding air to a considerable distance by a kind of carrying process or convection, which I have termed convective discharge, and if the hand be placed in the vicinity'a breeze is distinctly felt, representing a stream of elec trified air particle's. Any body placed within reach of the stream of air )articles receives an influx of electricity of the same polarity as that'of the charged conductor, which continuesuntil the body has acquired a potential approximatelythe same-as that of the conductor. I

If'thebody previously had a charge of opposite sign to that of the conductor, this charge is quickly neutralized and then reversed,the influx being slower and slower as the body ap roaches the potential of the charged cond iictor'. If, however, asecond conductor of small surface be laced near the first and connected to the ot er pole of the Wimshurst machine, so that the body is at of both conductors, there is a neutral limitation to the transfer of electricity, because when the zero condition is reached in the body there is an equal tendency to transfer electricity from both conductors. Any slight acquisition of charge either way from zero is quickly checked by the charge in the o posing conductor. This is due to the Wellown law by which the tendency to two bodies is proportional to the square of the difference of the two. Thus t e only stable condition of the surface under treatment is a condition of neutrality. To illustrate: Suppose the surface to be treated is charged with-positive electricity and brought within the influence of the two charged conductors. The tendency of a negative charge from the negative conductor to pass over and neutralize the positive charge of the charged surface is much greater than the tendency of the charge. of the positive conductor to add to the positive charge of the surface-in accord ance with the law already stated, and as a consequence the ositive char e of the charged surface will e immediate y'neutralized b the negative charge of the conductor. I an excess of negative electricity passes over, there is at once developed a tendency to draw positive electricity from the positive conductor, and this tendency is very much greater than the tendency of the negative electricity to pass over to a negatively-charged surface. Thus the tendency always isto maintain the surtransfer electricity across air between any potential existing between the same time within the range of influence minating in pointsor other small face in a neutral condition under the active influence of both charged conductors, and I have found from experience that the relative position of theseconductors and the charged surface is immaterial so longas the surface comes within the i fluence of both conductors. v

I illustrate'm invention b means of the accompanying awing, whic shows a diagram i lustrating the application'ofmy proc- (ass to a web of pa er.

0 represents a imshurst machine to the tlwo poles ofwh ich are connected wires b b, t ese wires being in turnconnected to two conductors c 0. These 0 ndu'ctors may be simply small wires,- as here shown, or they, may be metallic conductors of any' form tersurfaces, from which the discharges take place into the air. They are located sufiiciently near each other to allow of a convective discharg through the air from one conductor 'to an other and sufficiently far apart to maintain opposing charges of high potential. I find in actual practice that-with a potential of say, five thousand volts they may be located at a distance of three-inches apart, and the distance between them, as is evident, will be governed by the potential of the current and the length of the sparking distance."

The web of paper (1 is made to pass under or near the conductors c c and at such a distance as to be within the common influence of both conductors. I find; for instance ,that when the conductors are placed three inches apart the paper to be treated will be neutralized at a distance of ten inches or less. The material to be treated is passed along continuously by the conductors, as in the case of a web of paper or yarn, roving, &c., or the article may be brought near the conductors and then removed according to circumstances. I

While I have shown a Wimshurst machine as the source of the electric charges for performing the process, any other convenient source may be used, and even an alternating transformerofhigh voltage might be use by applying to it a rectifier of any of the well known kinds which would send all of the with a ch positive impulses to one wire and all of the negative impulses to the other Wire, thus kee ing each of the two wires charged always Wit the same polarity. It does not prevent the proper workin of the process if the voltage varies somew at, as it would when fed from an alternating transformer through a rectifier, as above described.

The two conductors maybe wires, as here shown, or they may be of any form or size, provided they have small surfaces or projecting portions capable of discharging electric= ity intd the atmosphere, such as a series of sharp points.

claim 1. The herein-described process of neutralizing static electricity on a givensurface by chaiging a pair of conductors presenting small surfaces or promoting points to the air, on e with la charge of positive and the other arge of negative electricity of high Voltage nd constant polarity and located so that. a given point on the surface to be treated may be brought within the range of convective discharge of both conductors at the same time and sufiiciently far apart to maintain opposing charges and bringing the surface. to be neutralized simultaneously within the active, influence of both conductors.

2-. The herein-described process of neutralizing static electricity on a given surface by'charging a pair of wires, one with a charge of positive and the other with a charge of negative electricity of high voltage and constant polarity andlocated so that a given point on the surface to be treated may be brought within the range of convective discharge of both wires at the same time and sufliciently far apart to maintain opposing charges and bringing the surface to be neutralized simultaneously Within the active infiuence of both wires.

Signed at Portland, Maine, this 24th day of October, 1904.

WILLIAM HENRY CHAPMAN. 

